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No. 623,625. Patented Apr. 25', I899. C. P. PUSHAW.

ELECTRIC BRAKE. (Application mea m 18, 139341 (No Model.) 2 Sheets8heet I.

No. 623,625. Patented Apr. 25, I899.

12. P. PUSHAW.

ELECTRIC BRAKE.

(App cation filed may 18, 1898 (No Model.)

2 Sheets-Sheet 2.

J 5140mm ms NORRS'PETERS PHD NlllE STATES it met.

ATET

ELECTRIC BRAKE.

SPECIFICATION forming part of Letters Patent N0. 623,625, dated April 25, 1899.

Application filed May 18, 1898. Serial No. 681,060. (No model.)

ington, in the District of' Columbia, have invented certain new and useful Improvementsin Electric Brakes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in electric brakes; and the objects of my invention are to provide means whereby the brakes may be almost instantaneously set at any required degree of pressure, to provide means for rigidly holding the brake in place after it has been set, andthis without the expenditure of any electric energy, and to provide a simple, inexpensive, and easily-operated electric brake.

\Vith these objects in view my invention consists in the construction and combinations of parts,as hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a top plan view of a car-truck, showing my electric brake applied thereto. Fig. 2 is an enlarged View, in side elevation, of the electric means for operating the brake. Fig. 3 is a diagram showing the electric circuits. Fig. 4 is a fragmentary view, partly in side elevation and partly in section, on the line i 4 of Fig. 5, showing a modification of the means for holding the brake in position after it has been set. Fig. 5 is a section taken on the line 5 5 of Fig. 4. Figs. 6 and 7 show other modifications of the means for holding the brake.

A represents a cartruck provided with brakes a, mounted on brake-beams and operated by brake-levers in the usual way.

13 is a solenoid attached to the truck in any desired manner, within which freely works a plunger 0. This plunger may be of any desired form in cross-section, but is shown as cylindrical, and it hasa slot 0 at its outer end, with which one of the brake-levers engages.

Mounted on the truck-frame, nearly over the plunger C and parallel to it, is a second smaller solenoid D, provided with a plunger E. The outer end of this plunger is connected to a wheel F, whose axle f is mounted in hearings in a frame H, supported from the car-truck. A strong spring G is attached to the wheel F and the covering of the solenoid B and tends to draw the plunger E out of the solenoid D. On one face of the wheel F, just over the plunger 0, are pivoted two friction clutches or slides f f These engage. the plunger C, one above and the other below, and have faces which accurately fit upon the plunger C.

In Fig. 3, R represents a source of electric energy of any kind, and .S and S the circuits through the solenoids. T and T represent switches whereby the current may be turned on or off from either of the solenoids at will.

The operation is as follows: When it is desired to set the brakes, the current is turned on through the solenoid D. The plunger E is thereby drawn in, releasing the clutches ft and f by the partial rotation of the wheel F. The current is then sent on through the solenoid B, and the plunger '0 is drawn in, setting the brakes. The current is then cut off from the solenoid D, and the spring G draws back the wheel F, bringing the clutches ff firmly against the plunger 0, holding it from movement. The current is then cut off from the solenoid B, thus saving electric energy, but the brake remains fixed. When it is desired to release the brakes, a current is sent through the solenoid D. This causes the plunger E to be drawn'in, moves the wheel F, and loosens the clutches f f The reaction of the brakes causes the plunger 0 to move outward. The current is then cut off and the brakes are held firmly out of contact with the wheels. Thus it will be seen that the current need only be used for a short time until the brakes are set and held, when it is cut off.

In Figs. 5 and (5 a modification is shown. K is an extension closely surrounding the plunger 0, and is provided with two slots in which the clutches f f are free to move. The shaftfis provided with shoulders f f and links f f are attached to these shoulders and to the clutches f and f.

In Fig. 6 is shown a modification in which the clutches are replaced by a spring or rope L, which is applied to the wheel F. Chains M M are attached to the plunger 0 and to the shaft f, so that as the shaft f revolves one chain is wound up and theother unwound.

In Fig. 7 is shown a modification of the form shown in Fig. 6. In this form the chain M instead of being wound upon the shaftf is wound upon a pulley N, which is loosely mounted on said shaft. A spiral spring a is fastened to the pulley N and to the shaft f. As the plunger 0 moves into the solenoid B the spring a is compressed momentarily and thenexpands, turning the shaftf and winding up the chain M. This arrangement is adopted to relieve the sudden strain upon the chain M and shaft fdue to a sudden movement of the plunger C in the operation of setting the brake.

It is obvious that many changes might be made in the construction without departing from the spirit of my invention, and I wish it to be expressly understood that I do not limit myself to the exact details shown and described.

Having thus described my invention, .what I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In an electric car-brake, the combination of brake-levers, a main solenoid, a plun-.

ger therein connected to the brake-levers, bearings mounted on the exterior of said solenoid, an axle journalcd in said bearings substantiallyat right angles to said plunger, a wheel mounted on said axle; a second solenoid, provided with a plunger, mounted parallel to the main solenoid but oppositely arranged and located on the opposite side of the wheel from the main solenoid, a spring attached to the main solenoid, connections between said spring and the plunger working in the second solenoid, and means for holding the plunger of the main solenoid in one of several possible adjusted positions, substantially as described.

2. In an electric brake, the combination of brake-levers, a plunger connected thereto, a solenoid in which said plunger is adapted to reciprocate, a wheel and axle, chains attached to said axle and to said plunger and running in opposite directions, and means for holding said wheel and axle in one of several possible adjusted positions,substantially as described. 3. In an electric brake, the combination of brake-levers, a plunger connected thereto, a solenoid in which said plunger is adapted to reciprocate, a wheel and axle mounted substantially at right angles to said plunger, chains connected to said plunger and to said axle and running in opposite directions, a spring or rope adapted to engage the circumference of said wheel, and means for bringing said spring or rope into or out of contact with said wheel, substantially as described.

4. In an electric brake, the combination of brake-levers, a plunger connected thereto, a solenoid in which said plunger is adapted to reciprocate, a wheel and axle arranged at substantially right angles to said plunger, chains connected to said axle and said plunger, a spring or rope adapted to be brought into contact with the circumference of said wheel, a second solenoid, a plunger adapted to reciprocate therein connected to said spring or rope, and means for withdrawing the plunger from the second solenoid when the cur rent is cut off therefrom, substantially as described.

5. In an electric brake, the combination of brake-levers, a plunger connected thereto, a solenoid in which said plunger is adapted to reciprocate, said solenoid being provided on its exterior with extensions,an axle journaled in said extensions, a wheel carried by said axle, chains connected to said axle and to said plunger, a spring or rope adapted to engage the circumference of said wheel, a second solenoid,a plunger adapted to reciprocate therein connected to said spring or rope, and a spring connected to said plungerand operating to withdraw it from said second solenoid when the electric current is cut off therefrom, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

- CHARLES I PUSIIAW.

Witnesses:

J STEPHEN GIUs'rA, JOHN H. HOLT. 

